Health

Effects of obesity on aerobic fitness in adolescent females

Article Abstract:

Obesity, or excess body fat, in adolescents is associated with decreased performance results on tests of aerobic and muscular fitness. There are several hypotheses concerning the relation between obesity and decreased cardiovascular fitness. The two major ones are that either obese adolescents have normal cardiopulmonary responses to exercise, but the excess weight they carry decreases performance or that the excess fat interferes with cardiopulmonary functioning. Understanding how obesity affects aerobic fitness is important for prescribing the proper exercise program needed to improve such fitness. This study assessed how obesity affects aerobic fitness in adolescent females. Tests for cardiopulmonary fitness and body fat percentage were performed on 27 female high school students. Subjects were placed into obese or nonobese groups, based on body fat test results. Results showed that aerobic fitness levels of the obese subjects were significantly lower than expected with an average maximal oxygen uptake of 30.9 milliliters per kilogram (mL/kg) per minute versus a norm of 40 to 45 mL/kg per minute. Absolute values for oxygen uptake were higher in the obese subjects, but were lower when related to body weight. Oxygen consumption and treadmill time decreased as body fat levels increased. Obesity was not associated with adverse effects on ventilation or the cardiopulmonary system. These results indicate that cardiopulmonary capacity is increased in obese adolescent females, but the excess fat results in a load that decreases performance. Exercise programs prescribed for these individuals should be geared toward increasing calorie expenditure and stimulating weight loss rather than increasing aerobic fitness. Using calories through exercise and losing weight are more important for obese adolescent females than improving aerobic fitness. (Consumer Summary produced by Reliance Medical Information, Inc.)

Body image and eating behavior in adolescent boys

Article Abstract:

It has been documented that the incidence of eating disorders among girls is associated with a desire to be thin. However, the incidence of abnormal eating behaviors in boys that is related to body image has not received similar attention. A study was conducted with 895 adolescent boys, aged 12 to 22. In response to questionnaires, 42 percent of the boys indicated that they were dissatisfied with their current weight. Only 22 percent believed they were overweight, although 40 percent actually were overweight. Eighteen percent thought they were underweight, while only ll percent actually were underweight. Out of 135 normal weight boys who were dissatisfied with their weight, 68 percent considered themselves underweight, and 32 percent thought they were overweight. Out of the total group, 33 percent were dissatisfied with body shape; 50 percent of these boys wanted to reduce the size of their waist (most of this group was overweight); 40 percent wanted to increase the size of their chest; and 43 percent wanted to increase the size of their arms. In contrast to the girls, the emphasis in adolescent boys appeared to be on increasing rather than reducing body size. Many boys who were dissatisfied perceived themselves to be underweight and underdeveloped; a preference for flat abdomens and 'hard' bodies was also noted. Boys who were dissatisfied with their weight or shape engaged in binge eating and binge drinking much more often than those who were satisfied. There were no significant differences in eating or weight control patterns among the adolescents wanted to gain weight and those who wanted to lose weight. Dieting was uncommon among the boys, as was the pattern of fasting and self-induced vomiting that occurs in adolescent girls. Binge eating was most often observed in basketball players and wrestlers. (Consumer Summary produced by Reliance Medical Information, Inc.)

Risk factors for adolescent cigarette smoking

Article Abstract:

Studies show that 20 percent of high school senior girls and 16 percent of boys smoke cigarettes daily. Several risk factors for cigarette smoking in adolescence have been identified, the most important of which is having friends who smoke. Other risk factors include the adolescent's relationship with parents, the level of supervision by parents, involvement in extracurricular activities, school performance, and attitudes about smoking and its consequences. Factors that influence future smoking behavior and the effects of these factors over time were assessed. The relationship of various behavioral and social factors to smoking behavior was examined in 443 students, who were assessed from early to late adolescence. Association with friends who smoked and previous smoking behavior had the greatest influence on future smoking behavior. Attachment to mother or father, supervision by parents, extracurricular activities, perceptions about the consequences of smoking, and academic involvement influenced smoking behavior in late adolescence. These findings suggest that approaches to controlling smoking behavior should focus on factors within the child's home and school environment as well as on the individual child. (Consumer Summary produced by Reliance Medical Information, Inc.)